Densification behavior, microstructure, and electrical properties of sol-gel-derived niobium-doped (Bi_(0.5)Na_(0.5)) _(0.94)Ba_(0.06)TiO_3 ceramics

摘要

Superfine powders (~100 nm) with compositions of (1 - x)(Bi _(0.5)Na_(0.5))_(0.94)Ba_(0.06)TiO_3 + xNb~(5+) (BNTBT6 + xNb) with x from 0 to 0.02 were synthesized by an improved citrate sol-gel method using Nb_2O_5 as Nb ~(5+) source. The sintering behavior, microstructure, and various electrical properties of BNTBT6 + xNb ceramics were investigated. The results indicated that the addition of a small amount of Nb~(5+) has no remarkable effect on the crystal structure and grain morphology, but the electrical properties of the ceramics are obviously influenced. The BNTBT6 + 0.005Nb compositions exhibit enhanced densification behavior and improved electrical properties of a piezoelectric constant d _(33) ~ 205 pC/N and a planar electromechanical coupling factor k _p ~ 33%.